MICE Superconducting Solenoids: Status and

UpdateRAL:T W BradshawM CourtholdJ RochfordM HillsD BaynhamOxford:J CobbW LauS Yang

2010-06-08 MICE Superconducting Solenoids TWB.pptx

Berkeley:M GreenS VirostekM ZismanHarbin:H Pan

X K Liu

L Wang

X L Guo

H Wu

A B Chen

Introduction

• Brief overview of the magnet system

• Status of the coils

Coil # Sponsor

Decay Solenoid 1 PSI (Switzerland) UK integration installation and commissioning of helium plant

Absorber and Focus Coil

3 UK – Oxford University and Rutherford Appleton Laboratory – built in UK

Spectrometer Solenoids

2 US LBNL – built in US

Coupling coils (flip coils)

2 US LBNL – built in China Harbin Institute of Cryogenics and Super Conductivity Technology

Upstream on Beam Line (not part of cooling channel)

Magnet Positions

Position of the Magnets in the MICE Hall

Decay Solenoid

Component of the beam line so not part of the MICE lattice

Installed in wall of MICE hall

Unusual in that is cooled with supercritical helium at 4.5K

Field 5T at 870A 1.1MJ

• Area 1.8x3.2mm2

• Cu:Sc 3.5• Icritical 1000 A• Bcrit (from model)

5.9T• So Jcrit of

superconductor 781A/mm2 @ 5.9T and ~4.2K

Solenoid in hall at PSI This was used on a muon channel at PSI and was operated from December 1974 until 2004

Decay Solenoid– 5T Superconducting Solenoid– 115mm bore, 5000mm length, constructed from 10 spools– Designed and built at the Paul Scherrer Institut (PSI) in the

1970s– Cooled by supercritical helium gas to approx. 4.8K– Critical current at 4.8K = 1000A, require 870A for 5T– Requires approx. 23W of cooling power

Decay Solenoid

– Transfer Line comprises 4 vacuum jacketed process lines (4K feed and return + 70K feed and return)

– Many metres of ancillary pipework between cold box, decay solenoid and the gas panels

– Buffer Tank stores the make-up gas required as liquid is formed in the magnet

– Magnet Current provided by 4 large cables between the power supply on the north mezzanine and the magnet turret

Decay Solenoid

• Part of the solenoid radioactive when supplied from PSI

• Replaced “hot” outer nose

• Work on plumbing, power supplies, quench detection ....

• Refrigerator supplied from Linde

• System worked well until we had the refrigerator serviced – leaks, gas purity etc....

......but now back in operation

MICE Lattice

Spectrometer

Spectrometer

Absorber Focus Coil

Absorber Focus Coil

Absorber Focus Coil

Coupling Coil

Coupling Coil

Note – all magnets in lattice use closed cycle coolers for refrigeration

MICE Lattice

SS AFC CC AFC CC AFC SS

Spectrometer Solenoid

This is the most complicated of the MICE coils

Comprises

1 x centre coil

2 x end coils

2 x matching coils

Spectrometer Solenoid

Magnet has been run at Wang NMR with training as follows 165, 219, 238, 253, 257 A (required current is 275A)

M2 coil open circuit between feed-through on the internal cryostat and the coil.

Magnet is now being disassembled and review board convened to assess the problems

The other spectrometer solenoid (#1!) is awaiting final assembly

This will cause a delay while the problems are being understood

Absorber and Focus CoilThe Absorber and Focus Coil Solenoid consists of two coils on a bobbin

Has to accommodate the hydrogen absorber and safety windows

Closed cycle coolers used on both the magnet system and the hydrogen condensing system

Absorber and Focus Coil

Status

• Completed reviews prior to manufacture

• Thermal model

• Mechanical issues around bobbin material and strength

• Quench protection etc....

Just entering the manufacturing phase with the first coil to be wound in the next few weeks.

First delivery Jan 2011

Second delivery April/May 2011

Third ??? (required 2013)

Coupling Coils

In the process of manufacture by Harbin Institute of Cryogenics and Super Conductivity Technology under contract from Lawrence Berkeley

These will be integrated with 201MHz RF cavities to form the RFCC – RF coupling coil modules.

Length 285mmInner rad750mmLayers 96Inductance 593 HCurrent 210/198A(flip/non flip)

Status:

Design completeIn manufacture

Because of large stray field position and orientation of HTS leads important – need to keep field // to the flat face of the conductor

Summary

The components of the MICE lattice and beam line are in various stages of manufacture and production

MICE – unusual for a particle physics experiment in that all the magnets are cooled by cryocoolers

Decay solenoid – in position and operational

Spectrometer solenoids – due early 2011 – on critical path

Absorber and focus coils – first one Jan 2011 (required Q3 for Step IV)

Coupling coils – required 2012 for Step V (with one rf module)

END